Sewing-machine.



w. A. MACK. SEWING MACHINE.v

APPLlCATION FILED AUG-2L 1912.

Patented May 30,1916.

WILLIAM A. MACK, OF CLEVELAND, OHIO, ASSIGNOR TO THE. STANDARD SEWING MACHINE COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

SEWING-MACHINE.

Specification of Letters Patent.

Patented May 30, 1916.

Application filed August 27, 1912. Serial No. 717,243.

To all whom it may concern Be it known that I, VVILLIAM A. MACK, a citizen of the United States, and resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Sewing- Machines, of which the following is a specification.

In the operation of sewing machines, the needle-thread loop when being drawn up by the take-up subsequent to its cast-01f by the loop-taker is liable to twist upon itself and interfere with the sewing operation by preventing the loop being properly drawn up into the work, in which event the thread is liable to be broken under the pulling action of the take-up, or if this does not occur, an objectionable looking bunch of thread formed by the twisted loop is left at the under side of the work. To provide means for controlling the needle-thread loop while being drawn up by the take-up subsequent to its cast-off by the loop-taker and preventing such undue twisting of the same has been one of the main objects of my present invention.

In the operation of sewing machines of the type in which a rotary loop-taker is operated to have a plurality of revolutions to each reciprocation of the needle, such for example as that disclosed in Letters Patent #1,005,250, issued to me October 10, 1911, it sometimes happens that the needle-thread loop after being cast off by the loop-taker during its first revolution, is not drawn up sufficiently or otherwise controlled in its position to prevent its being caught by the point of the loop-taker on the second or idle revolution of the latter, in

which event the thread is broken and the sewing operation interrupted. To provide a simple and effective means for controlling the position of the thread loop and guarding against its being caught and broken by the loop-taker on its second or idle revolution has therefore been a further object of my invention.

Both of these objects I attain in a machine of the particular type referred to, that is, in a machine in which a rotary-loop-taker is operated to have a plurality of revolutions to each reciprocation of the needle, by providing thenon-rotary bobbin-case carried by the looper with a projecting member so formed and positioned as to engage the thread-loop while it is being drawn up by the take-up subsequent to its cast off by the loop-taker and control the same in the desired manner referred to.

Referring now to the accompanying drawings forming part of this specification, in which I have shown only so much of a sewing machine as is necessary to illustrate my invention, Figure 1 is a front end elevation of a sewing machine embodying my invention, showing the parts in position at the time the thread-loop is being cast off by the loop-taker, and Figs. 2 and 3 are detail front and side views respectively 'of the loop-taker and supported bobbin-case, illustrating the control and positioning of the thread-loop by the loop-engaging member on the bobbin-case in accordance with my 111- vention.

Similar reference characters indicate like parts in the several figures of the drawings.

My invention may be applied to sewing machines of more or less substantial difference in construction and operation,rbut it has been applied by me to, and is here shown in connection with, a sewing machine of the type disclosed in my aforesaid Letters Patent #1,005,250, which machine comprises a bed-plate 1, an overhanging bracket-arm 2, a vertically reciprocating needle-bar 3 mounted in said bracket-arm, a reciprocating take-up 4. also mounted in said bracketarm, a rotary loop-taker 5 carried by a shaft 6 at the under side of the bed-plate and adapted to be operated by suitable means (not shown) to have a plurality of revolutions to each reciprocation of the needle, said loop-taker being provided with a circular race-way formed therein at its face side, and a non-rotary bobbin-case 7 removably seated in said raceway of the loop-taker. These several parts are substantially the same in construction, operation and function as the similar parts in the machine of my aforesaid patent.

In one embodiment of my invention I provide the bobbin-case at its upper side with a radially projecting member 8 which, when the bobbin-case is in operative relation with the loop-taker as shown, is located in position exteriorly of said loop-taker and at the right of the path of the needle when viewing the machine from the front end thereof, as shown in Fig. 1, whereby said member will engage the thread-loop t after the latter has been drawn up by the take-up from its encircling 'position about the bobbin-case as shown in Figs. 2 and 3, and maintain it in open or spread condition sufliciently long to prevent undue twisting of the same prior to its being drawn up into the work. In the performance of such function the member 8 acts as a loop-spreader and I have therefore so termed it herein.

It will be noted that the member 8 extends toward and substantially to the point at which the loop is cast oil by the loop-taker. The loop is cast oif by the loop-taker hook at about the time the hook reaches the position shown in Fig. l, but the loop is held in open or spread condition by the body of the bobbin ease up to the time that the end of the loop is substantially adjacent to the extremity of the member 8.

In the normal operation of the machine to which my invention is applied the take-up draws the thread-loop above the path of the loop-taker in advance of the latter completing its first revolution and so prevents the same being caught and broken by said looptaker on its second or idle revolution. In the event of the thread-loop not being so controlled or drawn up however, through failure of the usual thread-controlling devices to act in their intended or normal manner, it will in the present case be engaged and held above the path of movement of the loop-taker hook by the outer edge of the member 8, as shown in Figs. 2 and 3, said edge presenting a cam surface 9 which projects slightly beyond the path of movement of the loop-taker hook and serves, in the manner stated, as a guard to prevent the thread-loop from being caught by said hook.

What I claim is:

1. In a sewing machine, the combination with a take-up and a rotary loop-taker having a raceway, of a non-rotary bobbin case seated in said raceway of the loop-taker and provided with an elongated surface extending toward and substantially to the point at which the thread loop is cast off by the loop-taker, that part: of said surface in the vicinity of said point of cast off of the loop by the loop-taker being designed to catch the end of the thread-loop after it is cast off by the loop-taker, and the entire surface serving to maintain the thread loop in open or spread condition after receiving from the loop-taker until it is substantially drawn up by the take-up, said surface extending radially beyond the race-bearing surface of the bobbin case, for the purpose described.

2. In a sewing machine, the combination with a take-up and a rotary loop-taker having a raceway, of a non-rotary bobbin case seated in said raceway of the loop-taker and provided with an elongated surface in a plane at one side of and adjacent to the path of movement of the loop-taker hook, said surface extending toward and substantially to the point at which the thread loop is cast off by the loop-taker, that part of said surface in the vicinity of said point of cast-off of the loop by the loop-taker being designed to catch the end of the thread-loop after it is cast off by the loop-taker and the entire surface serving to maintain the thread loop in open orspread condition after receiving it from the loop-taker until it is substantially drawn up by the take-up, said surface extending radially beyond the race-bearing surface of the bobbin case, for the purpose described.

Signed at Cleveland, in the county of Cuyahoga, and State of Ohio, this 22d day of August, A. D. 1912.

WILLIAM A. MA CK.

WVitnesses:

CHAS. C. EMMONS, J. H. WHITE.

fiopies of this patent may be obtained for five cents each, by addressing the "Commissioner of Fatenis,

Washington, D. C. 

